Incased fuse



Nov. 24, 1925.

T. E. MURRAY INCASED FUSE l Filed April 4, 1921 .40., electric weldirPatented Nov. 24, 19255. i

THOMAS' E. MURRAY, or nnooxmm, NEW Yoan.

moesen FUSE.'

Application led April 14, 1921. Serial No, 458,353.

l T all .whom it may concern."

Be it known that I, THdMAs E. MURRAY,-

a citizen of the United States, and4 residentA of Brooklyn, New York,have invented certain new and useful Improvements in Incased Fuses, ofwhich the following is a specification.

My invention aims to provide an incased electric fuse which can becheaply manu- `factured and which has other advantages referred to indetail hereinafter. v A

Fig. 1 is a perspective view of a complete incased fuse; j v vFig. 2 isahorizontal section ofthe same with the fuse strip removed;

Fig. 3 is a yvertical section with the fuse strip in place;

Fig. 4 is a transverse section on the' line 4 4 of Fig. 3, with the fusestrip omitted.

$0 The fuse proper which I have indicated at A may be 'of any usual orsuitable type.-

It is preferably of the construction described in the atent of Murrayand Murray, dated Novem r14th, 1922, No. 1,435,651. It con- 5 sists ofa'strip of fusible metal withf-forked ends B for attachment to terminalsandwith the usual contractedcentral portion and an 4envelope of asbestosor other refractory insulating material extended over it continul ouslybetween its terminals.- This covers the contracted ortion atA thecenter, where Athe fuse melts t roughv in use, and prevents arc-' ing orthe passage of current from the broken end' of the fuse outward and thusIl permits the use of a metal casing which l .would `otherwise bedangerous.

The case consists of a metal box with sides 1, ends 2. andan arched` top3 and a flat bottom 4, tle parts being put together by (as by drawingthe top, sides and ends 1nI one piece and welding the bottom on,a or byforming two halves and weldin them together on a Icentral longi' tudinplane) or in an other usual'or suitable way. In the en sI of the casingare porcelain insulating blocks 5 extending outward Aand inwardbeyond-the metal and held' against removal outward by` shoulders 6 onthe inside and cemented with plaster '62 Each block carries a conductorof copper extending outward in the form of a lat blade 7 adapted foreasy insertion between `the blade terminals of the line intowhich thefuse is to'be inserted. Within the case the terminals have their ends 8bent-at an angle, 55

`as shown, and preferably in a plane transverse to the plane of theouter` portions or blades 7 the "inner ends 8 being threaded for screws9 which fasten 4the terminals of the fuse vstrip with the latter in thearched 50 position shown.

The bottom 4 of the box is provided with an opening 10 through whichv ascrew driver may be inserted to operate the screws 9, the ends 8 of theterminals being set at such an 55 angle as to facilitate this operation,and the opening 10 being large enough also to permit the ypassage of thefuse strip. The opening is normally covered by a plate 11 passingthrough afslot in the end of the box and 7. having an enlarged head 12by which it can be pressed in or can be pulled out tonn- Wer theopening. A wedge 13 is provided, by bending' up the bottom orvas aseparate piece, which-enga es the end of the cover u when the latter 1sshoved inward. The cover is provided with a slight boss 14 whichprevents its complete withdrawal through the slot in the endof the boxand which also locks it in positively under thel wedge 13, the latterforcing it down against the bottom of the box. y When a fuse burns outthe entire case will vbelifte'd'out of the terminals and will be openedat the bottom and.v a new fuse inserte Whileathe fuse is in place ythe oening at the bottom is generally inaccess le because of its closeness tothe plate 15 on which the line terminals, indicated in dotted lines atl,are mounted, The entrance ofthe box is thus concealed andprotected.V

Though I have described with greatparticularityvof detail certainspecific embodiments of my invention, yet 1t Ais not to be understoodthat the invention is restricted to "the particular lembodimentsdisclosed. Various modifications in detail'thereof may be made by thoseskilled in the art without departure from the invention as. defined inthe followingclaims, 1- 100 That I claim is insulating blocks carried inthe ends thereof 1. A fuse casing carrying terminals passwith a spacesurrounding them and a plast-ie 10 ing through the opposite ends thereofin filler within the easinr between the insulatcombination with anarched fuse strip Withing' blocks and the metal. 5 in the easing, said.casing havingr an opening In witness whereof, I have hereunto signed onthe concave side of the strip through my name. which the latter may beremoved or inserted.

y 2. A fuse casing comprising a metal box, THOMAS E. MURRAY.

